Hvac, heating, ventilation, air condition, is used in buildings and ships. The ventilation may be a machine or gravity based ventilation, or a hybrid. Such a ventilation system often comprises a hvac damper, which is an example of a closure or a shutter of the ventilation ducts. Examples of the hvac dampers may be fire and/or gas dampers. Hvac dampers are passive fire protection products used in hvac ducts to prevent damage or undesired actions, such as the spread of fire inside the ducts through fire-resistance rated walls and floors. Hvac dampers are similar to fire dampers in fire resistance rating, and also prevent the spread of smoke inside the ducts. For example, when a rise in temperature occurs, the hvac damper shuts-off and closes, usually activated by a thermal element, which melts at temperatures higher than ambient, but low enough to indicate the presence of a fire, allowing springs to close the damper blades. Dampers can also be closed following a receipt of an electrical signal from a fire alarm system utilizing detectors remote from the damper, indicating the sensing of heat or smoke in the building occupied spaces or in the hvac duct system.
Hvac dampers can be controlled by an machine driven actuator or manually open and closed positions. When at a start-up phase, or when a fault occurs, power is not always available for use, such as there is no compressed air or electricity, which is needed in order to obtain an open position for the damper actuator, for example in order to ensure an air supply. It may be required that a user is manually setting the damper in a normal operating position, in case manual use is available. Unfortunately, the manual use enables that the damper is forgotten in the open position. In this case, the damper does not operate in a fault situation as desired, for example it may not close when needed. In addition, the manual use can be a difficult and cumbersome, due to, for example, hvac systems in confined spaces.
If the damper is not equipped with a manual use capability, the damper can be opened using battery power and/or a portable pressure tank. A canister of compressed air or the battery pack can be used to open the damper. Battery or compressed air bottle is an expensive and complex. An advantage of the battery or the compressed air bottle is that the damper cannot remain in the open position, if the fuse of the damper has been triggered.